Automatically controlled immersible electric coffee maker



A April 5, 1967 c. H. WICKENBERG ETAL 3,316,388

AUTOMATICALLY CONTROLLED IMMERSIBLE ELECTRIC COFFEE MAKER Original FiledJune 14, 1961 6 Sheets-Sheet l H ZflINYENTORS:

Gm a 1J2 I A ril 25, 1967 c. H. WICKENBERG ETAL 3,316,388

AUTOMATICALLY CONTROLLED IMMERSIBLE ELECTRIC COFFEE MAKER 6 Sheets-Sheet2 Original Filed June 14, 1961 VINVENTORS:

32am Q April 1967 c. H. WICKENBERG ETAL 3,316,388

AUTOMATICALLY CONTROLLED IMMERSIBLE ELECTRIC COFFEE MAKER Original]Filed June 14, 1961 6 Sheets-Sheet 5 IE :I 614 IN VEN TO 5 April 25,1967 c. H. WICKENBERG ETAL 3,316,388

AUTOMATICALLY CONTROLLED IMMERSIBLE ELECTRIC COFFEE MAKER Original FiledJune 14, 1961 6 Sheets-Sheet 4.

A ril 25, 1967 c. H. WICKENBERG ETAL 3,316,388

AUTOMATICALLY CONTROLLED IMMERSIBLE ELECTRIC COFFEE MAKER Origina] FiledJune 14, 1961 6 Sheets-Sheet 5 IN V EN TORS:

' A ril 25, 1967 c. H. WICKENBERG ETAL 3,316,388

AUTOMATICALLY CONTROLLED IMMERSIBLE ELECTRIC COFFEE MAKER Original FiledJune 14, 1961 6 Sheets-Sheet 6 r INVENTORS:

United States Patent 3,316,388 AUTOMATICALLY CONTROLLED IMMERSIBLEELECTRIC COFFEE MAKER Chester Wickenberg, Elgin, and Moises B.Lorenzana, Glen Ellyn, Ill., assignors to Sunbeam Corporation, Chicago,Ill., a corporation of Illinois Original application June 14, 1961, Ser.No. 117,079, now Patent No. 3,224,360, dated Dec. 21, 1965. Divided andthis application May 18, 1964, Ser. No. 368,159 7 Claims. (Cl. 219-442)This application is a division of our copending application Serial .No.117,079, filed June 14, 1961, now US. Patent No. 3,224,360, and assignedto the same assignee as the present application.

The present invention relates to automatically controlled heatingdevices and, more specifically, to automatic cooking devices such asbeverage brewers and coffee makers of the type in which the heatingmeans is automatically controlled during the coffee making operation.

Beverage brewers and coffee makers of the so-called vacuum type such asdisclosed in Jepson Patent No. 2,312,555 have been extensively usedheretofore, and there are many people who believe that this type ofcoffee maker is superior to all other types. In general, this vacuumtype of coffee maker comprises a lower heating chamber or vessel and anupper coffee infusion chamber or vessel. Conventionally, water is placedin the lower heating chamber while the coffee grounds are placed in theupper chamber. As the water is heated in the lower chamber, water vaporpressure is created above the liquid in this chamber which, when thetemperature of the liquid approaches the boiling point of water, forcesthe water from the lower chamber into the upper chamber to infuse thecoffee grounds contained therein. When the heat is removed from thelower chamber it cools so that the water vapor contained thereincondenses to create a vacuum, thereby causing the hot water which hasinfused the coffee grounds, and now is really coffee, to be drawn backfrom the upper chamber through a suitable filter into the lower chamberwhere it is preferably maintained at a desired serving temperature whichCOlLlld be of the order of 160, 180 or the like.

It will be understood that in automatic coffee makers of the typereferred to above it is essential that the heat supply to the heatingchamber be cut off when the water has substantially all been forced intothe upper chamber. If this cutoff action occurs too soon, substantiallyall of the water will not have been forced to the upper chamber and thecoffee will be diluted by the water remaining in the lower chamber whenthe coffee returns to the lower chamber. On the other hand, if thecutoff action is delayed for any appreciable period of time after allthe water is forced out of the lower chamber or vessel, damage ordestruction of the coffee maker may result. Actually, there have been onthe market two types of automatic coffee makers embodying the so-calledvacuum principle. In one type the chambers are made of metal and theheating element is built into the bottom of the lower metal chamber. Anexample of this type of coffee maker is disclosed and claimed in theabove-mentioned Jepson Patent No. 2,312,555 assigned to the sameassignee as the instant application. In this type of coffee maker itwill readily be understood that when substantially all of the water hasbeen forced from the lower chamber, a very rapid increase in thetemperature of the bottom of the lower metal vessel will result and suchrapid increase in the temperature of the lower vessel is utilized toactuate a thermostatically controlled switch for shutting off the heatat the proper time. The present invention is concerned with this type ofcoffee maker and,

3,316,388 Patented Apr. 25, 1967 hence, it is unnecessary to discuss theproblems of control of automatic vacuum type coffee makers where glassvessels are employed.

The automatic coffee maker of the above-mentioned Jepson patent has beena very successful device commercially and coffee makers of that typehave been extensively :sold throughout the world. The present inventionis in the nature of an improvement on the coffee maker disclosed in theabove-mentioned Jepson patent.

For proper operation of such vacuum type coffee makers it has beenimportant to provide a good seal between the upper and lower vesselsduring the coffee making cycle and, as disclosed in the above-mentionedJepson patent, a suitable tight fitting resilient sealing ring has beenemployed for this purpose. Although this arrangement has been verysatisfactory, a problem is presented in the removal of the uppervessel-upon completion of the coffee making operation. The housewifemust break the tight fitting seal between the upper vessel and the lowervessel by applying a considerable amount of force to physically pull thevessels apart and when both vessels are hot, this is somewhat of aproblem. It would be desirable to provide an arrangement where thevessels may be separated upon completion of the coffee making operationwithout the requirement of any force in breaking the seal and yetwherein a good seal is provided to maintain the vacuum type operation.

The modern trend in cleaning cooking devices has been to make it assimple as possible for the householder to clean such devices after use.It would be desirable to provide a vacuum type automatic coffee makerwherein both vessels may be completely immersed for washing without anydeleterious effect on the automatic control incorporated therein.

Accordingly, it is an object of the present invention to provide a newand improved automatic coffee maker.

It is another object of the present invention to provide an improvedseal between the two vessels of a vacuum type coffee maker.

It is a further object to provide a vacuum type coffee maker withimproved, readily releasable locking means for locking the upper andlower vessels together. I

Still another object of the present invention resides in the provisionof improved control means for an automatic coffee maker of the vacuumtype.

A further object of the present invention is to provide an improvedautomatic coffee maker which is completely immersible in liquid forcleaning purposes.

A still further object of the present invention resides in an improvedautomatic coffee maker which is simple and sturdy in construction,economical to manufacture and which is capable of giving long years ofsatisfactory and foolproof service.

Further objects and advantages of the present invention will becomeapparent as the following description proceeds, and the features ofnovelty which characterize the invention will be pointed out withparticularity in the claims annexed to and forming a part of thisspecification.

For a better understanding of the present invention reference may be hadto the accompanying drawings in which:

FIG. 1 is a perspective view of an automatic coffee maker of the vacuumtype employed in the present invention wherein the upper and lowervessels are shown retained or locked in sealed relationship as would bethe case during a coffee making operation;

FIG. 2 is an enlarged fragmentary sectional view taken on line 2-2 ofFIG. 1;

FIG. 3 is a fragmentary sectional view similar to FIG. 2, but showingthe releasable locking means in the released position; 4

FIG. 4 is an enlarged sectional view taken on line 4-4 of FIG. 1, butshowing the releasable locking arrangement in the condition of FIG. 3and with the switch in the open position;

FIG. 5 is an enlarged sectional view taken on line 5--5 of FIG. 4,assuming that FIG. 4 shows the complete structure;

FIG. 6 is a sectional view taken on line 66 of FIG. 5, again assumingthat FIG. 5 shows the complete structure;

FIG. 7 is an enlarged fragmenttary view of a portion of FIG. 4;

FIG. 8 is a somewhat schematic diagram illustrating the electricalcircuit of the automatic coffee maker of the present invention with thecontrol switch in the close position;

FIG. 9 is an enlarged view of a portion of the switch means of FIG. 5more fully to illustrate the switch assembly and shows the bimetallicelement in the heated and deflected conditions;

FIG. 10 is a sectional view taken on line 10-10 of FIG. 9;

FIG. 11 is a top plan view of the seal ring and one of the upper handlesassociated therewith; and

FIG. 12 is a greatly enlarged fragmentary sectional view taken on line1212 of FIG. 5.

Briefly, the present invention is concerned with an autobe readilyhandled by the operator when using it to pour coffee therefrom, asuitable handle 28 (FIGS. 1 and 6 of the drawings) is provided, theupper end of which is suitably secured to the vessel by fastening meanswell understood by those skilled in the art. This handle 28'preferablyis of the form sometimes referred to as a D handle including portions28a and 28b, the portion 28b conforming to the vessel wall, as bestshown in FIGS. 1 and 6, with the lower end of the handle havingprojection 28c (FIG. 6) for interlocking relationship with anotherportion of the coffee maker described hereinafter. The portion 28a is,of course, the hand grip portion. The handle 28 is preferably moldedfrom a suit-able phenolic resin or the like. In an embodiment built inaccordance with the present invention, the interior of the vesselportion 21 is provided with suitable indicia stamped into the vesselwall indicating the number of cups of coffee for different levels in thevessel. So that this indicia is only visible on the interior of thevessel 21, it is preferably defined in the wall portion thereof beneaththe portion 28b of the handle 28.

As is best shown in FIGS. 4, 5, and 6 of the drawings, the lower portionof the side wall of the vessel 21 terminates in an annular dependingflange 21a of somewhat matic coffee maker of the vacuum type havingupper and lower vessels, at least the lower one of which is formed ofmetal. A readily releasable O-ring seal is provided between the upperand lower vessels. This seal is provided with suitable locking meanswhich are actuated by a pair of handles serving also as the means forhandling the upper vessel or bowl. An improved temperature responsiveswitch of the snap acting type is provided which is simple and compactand which is manually actuated to the On position by means completelysealed with respect to the temperature responsive switch means. In otherwords, the entire control mechanism is completely sealed against theentrance of moisture so that the cooking vessel may be immersed forcleaning purposes.

Although the present invention is illustrated in the drawings asspecifically applied to an automatic coffee maker of the vacuum type, itshould be understood that certain features of the invention areapplicable to other types of coffee makers as well as other cookingdevices wherein a cooking operation may be controlled in the mannercontemplated by the present invention.

Referring now to the drawings, there is illustrated an automatic coffeemaker generally designated by the reference numeral 20 comprising alower water heating chamber or vessel 21 and an upper coffee infusionchamber or vessel 22. Preferably these vessels are made of metalalthough at least the upper vessel 22 thereof might be made of glass, asuitable plastic or the like. The upper vessel 22 defining the coffeeinfusion chamber is provided with the conventional depending tube 23which is adapted to be inserted into the lower vessel 21, as illustratedin FIGS. 1 to 4 of the drawings, to provide communication between thevessels 21 and 22. This tube 23 is preferably provided with a suitablesmall opening 24 (FIG. 4), such as is disclosed in the above-mentionedJepson patent, to prevent movement of the water in vessel 21 into vessel22 before this water is sufficiently heated.

As in the above-mentioned Iepson patent, the lower vessel 21 has an opentop secured to which as by brazing or the like is a circular uprightflange 26. In accordance with the present invention this upright flangeis preferably provided with a circular inwardly directed annular recessor groove 27. So that the lower vessel may be used as a pouring vesselwhen the coffee making operation has been completed, the upright flange26 preferably includes an extended portion, not shown, defining apouring spout. Moreover, so that the lower vessel 21 may smallerdiameter than the maximum diameter of the vessel 21, and the circularspace Within the annular depending flange 21a is closed by a bottom 30of somewhat conical shape with the lowest level portion thereof at thecenter of the bottom. The bottom 30 is likewise provided with adepending peripheral fi-ange 30a, the outer diameter of which issubstantially the same as the inner diameter of the depending flange21a. The depending flanges 21a and 30a are united in a liquid tight sealby means of a suitable brazing or similar operation so that effectivelythe bottom 30 is an integral part of vessel 21.

For the purpose of securing suitable temperature responsive controlmeans and the like to the bottom of vessel 21, there preferably isprovided a center stud 32 which extends through an opening defined inthe bottom 30 and which is also suitably brazed or otherwise secured tothe bottom 30 in a liquid tight manner.

The upper vessel 22 with its depending tube 23 is preferably formed ofmetal and is shaped to provide a pleasing appearance such as is shown inFIGS. 1 and 4 of the drawings. Moreover, as iilustrated in FIGS. 2, 3and 4 of the drawings, the vessel 22 includes a cylindrical dependingportion 22a having a diameter somewhat smaller than the diameter of thecircular flange 26 secured to the lower vessel and a lower opening of adiameter to receive the upper end of tube 23, the latter being providedwith protrusions 23a for positioning purposes. The tube 23 is suitablysecured to the cylindrical portion 22a as by a ferrule portion 33, bestshown in FIG. 4 of the drawings. In accordance with the presentinvention the cylindrical portion 22a is provided with an annularlyoutwardly directed recess 34 for receiving an O-ring 35 so that when thevessels 21 and 22 are assembled in operative relation for a coffeemaking operation, the O-ring 35 may be disposed in sealing relationshipwith respect to the annular grooves 27 and 34. The O-ring 35 ispreferably formed of a silicone rubber and of a quality that will notaffect the coffee from an odor or taste standpoint.

In order to lock the lower and upper vessels 21 and 22, respectively, insealed relationship, as shown in FIGS. 1 and 2 of the drawings, there isprovided a seal ring 37, best shown in FIGS. 2, 3, 4, and 11 of thedrawings, in the form of a circular annular disk of somewhat L-shapedcross section having 21 depending annular flange 37a and a pair ofdiametrically opposed upwardly extending ears 37b. The seal ring 37 hasan internal diameter such as to be slidably received on the cylindricalportion 22a of the vessel 22 and a pair of locking handles 38 areprovided so as to be pivotally mounted on the ears 37b as best shown inFIGS. 4 and 11 of the drawings. The.

locking handles 38 are preferably formed of a molded phenolic materialsimilar to the handle 28 and preferably of the same color and include abifurcated end with an integral pivot pin 38a extending across thebifurcations so as to define an opening 39 between the pivot pin and theportion of the handle defining the bifurcated end. The ears 37b arereceivable in the opening 39. The ends of the bifurcations designated at38b effectively define a pair of oamming surfaces which, when the handlemembers 38 are pivoted about the axis of the pivot pin 38a from theposition of FIG. 3 to the position of FIG. 2, the camming portions 38bengage the underside of the vessel 22, as clearly shown in FIG. 2 of thedrawings, and cam the sealing ring 37 downwardly in a manner tending toforce the O-ring out of the groove 34 and, thus, insure a good sealbetween the flange 26 defining the opening in lower vessel 21 and thecylindrical depending portion 22a of upper vessel 22.

It will be undcrstod that the locking members 38 are also handles forgrasping the upper vessel 22 and, since they are formed on an insulatingmaterial, the upper vessel can be lifted and moved about even when it ishot as is the case immediately following a coffee making operation.Preferably the contour of the handles or locking members 38 is such asto conform closely to the bottom portion of the upper vessel 22, asclearly shown in FIGS. 3 and 4 of the drawings, thereby providinghandles for firmly supporting the vessel.

It will be appreciated that the O-ring 35 disposed in recess 34 holdsthe seal ring 37 and consequently the handles 38 in assembledrelationship. If the O-ring is removed from the groove 34 for cleaningpurposes, the seal ring 37 and handles 38 become disassembled. In orderthat the seal ring 37 and handles 38 remain in assembled relationshipeven though the O-ring 34 is removed for cleaning purposes, a suitableretainer 40 may be provided which is suitably brazed or otherwisesecured beneath the cylindrical extension 22a to provide a projectingannular flange 40a of larger diameter than the seal ring 37.

As is conventional with coffee makers of the vacuum type and as isspecifically disclosed in the above-mentioned Jepson patent, the uppervessel 22 is provided with a suitable filter or strainer means generallydesignated at 42 (FIG. 4) disposed in the bottom of upper vessel 22 soas to retain the ground coffee which is placed therein and, thus,prevent the coffee grounds from entering the depending tube 23. Theparticular filter arrangement generally designated at 42 forms no partof the present invention but is disclosed and claimed in a copendingapplication of Chester H. Wickenberg and Moises B. Lorenzana, Serial No.120,740, filed June 29, 1961, now US. Patent No. 3,130,663, and assignedto the same assignee as the instant application. To hold the strainermeans 42 in the position shown in FIG. 4 of the drawings, therepreferably is provided a filter rod 43 and a coiled spring 44, thefilter rod 43 having a hook portion 43a at the lower end for engagingthe lower end of the depending tube 23. The coiled spring 44 then tendsto bias the filter means 42 into sealing engagement with the bottom ofvessel 22 above the cylindrical depending portion 220. The upper end ofthe filter 43 is provided with a portion 43b which may be engaged by theoperator in inserting and removing the filter as will readily beunderstood by those skilled in the art.

The upper vessel 22 is preferably provided with a top opening 45 of adiameter corresponding to the circular opening at the top of lowervessel 21 so that a common cover 46 may be employed. The cover 46 may beformed of a molded plastic with a suitable manually engageable knobportion 46a integrally formed therewith. Preferably, also, the cover 46is provided with a depressed central annular portion 46b surrounding theknob 46a and suitable slots 47 are provided sothat when the cover 46 isassociated with the lower vessel 21,

coffee may be poured through the slots in the cover 46. In order thatthe cover 46 may be removably latched to the lower vessel 21, it isprovided with a pair of diametrically opposed latch buttons 49 which arepressed by suitable leaf springs 50 into a latching position as shown inFIG. 4 of the drawings. Preferably the latch buttons 49 are receivablewithin the groove 27 in lower vessel 21 to removably latch the coverinto position. The latch spring 50 are preferably supported by suitableabutments 46c integrally formed with the cover 46 and effectivelydefining a groovelike recess for receiving the upperends of thesesprings. Moreover, the latching buttons 49 which have projectionsextending through suitable openings in the lower ends of the leafsprings 50 prevent the leaf springs from moving out of engagement withthe abutments 46c.

From the above description it will be apparent that an improved sealingarrangement has been provided between the lower vessel 21 and the uppervessel 22. This sealing arrangement is designed so that the cylindricalextension 22a with the O-ring 35 mounted thereon can readily be insertedin the circular opening in the lower vessel 21. Upon actuation of thelocking levers 38 from the. position shown in FIG. 3 to the positionshown in FIG. 2, the O-ring 35 is expanded so as to make good sealingengagement between the nested portions of the vessels 21 and 22. When itis desired to remove the upper vessel 22 upon completion of a coffeemaking operation, the user need merely release the locking levers 38moving them from the position shown in FIGS. 1 and 2 to the positionshown in FIGS. 3 and 4, whereupon the upper vessel may be removed bymerely lifting it upwardly with no force other than that to lift theweight of the upper vessel.

For the purpose of heating liquid contained in the lower vessel 21,there is provided a main heating element 52 which is in good heatexchange relationship with the underside of bottom 30 as best shown inFIGS. 4, 5 and 6 of the drawings. As illustrated, the heating element 52is preferably of the well-known sheathed form comprising an outer metalsheath 53 within which is disposed a resistance element 54 preferablydisposed in the form of a spiral coil and spaced and supported withinthe sheath 53 by suitable electrical insulating material 55 which alsoprovides a good heat conductor. The heating element '52 is arranged in acircular configuration as best shown in FIG. 5 of the drawings anddisposed closely adjacent the depending flange 30a of the bottom 30. Theends of the resistance element 54 of sheathed heating element 52 areconnected to terminals 56 and 57 extending out of the sheath 53, andthese terminals are illustrated as being closely adjacent to each otherand extend into a different plane from the main portion of the heatingelement 52. Only a single turn of the sheathed heating element 52 isnecessary since the bottom 3t) is preferably formed of a material havinga very high heat conductivity, such as sheet copper or the like.Moreover, the heating element 52 is brazed to the bottom 36 so aseffectively to comprise an integral part of such bottom.

Preferably and as disclosed in the above-mentioned Jepson patent, theautomatic coffee maker 20 is provided with an insulating base 60 formedof a suitable phenolic material or the like which is adapted to besecured to the bottom of vessel 21 by the center stud 32 andspecifically by means of a nut 61 engageable with the threaded end ofthe stud 32. The base 60 effectively defines a control chamber 62therein beneath the lower vessel 21. Essentially the base 60 is a saucershaped member having a circular rim portion with an annular peripheralrecess 63 defined therein for receiving a sealing gasket 64 forproviding a moisture tight seal between the rim of the base 60 and thebottom of vessel 21 engaged thereby as clearly shown in FIG. 6 of thedrawings. The sealing gasket 64 normally has the cross sectionalconfiguration, best shown in FIG. 7 of the drawings, when not stressedby being clamped against the bottom of vessel portion 21. An importantaspect of the present invention, as was mentioned above, resides in acompletely sealed arrangement whereby the lower vessel 21 may beimmersed in liquid for cleaning purposes. The gasket 64 thus insuresthat no liquid can enter the chamber 62 at the junction between the base60 and the vessel 21. It will be appreciated that the center stud nut 61engaging the center stud 32 applies the necessary compressive force tothe gasket 64-.

As illustrated in FIG. 6 of the drawings, the base 60 is provided with acentral opening 66 and the bottom of the base concentric with theopening is provided with a first counter sunk portion for receiving aspring washer 67 and a slightly deeper counter sunk portion forreceiving an O-ring 68, the latter being necessary to seal the centralopening 66 against the entrance of moisture. The center stud nut 61 isillustrated as having a shank portion 610 extending into the opening 66for threadedly engaging the stud 32, and when the stud nut 61 is in theposition indicated at FIG. 6 of the drawings clamped against a stop nut69, a seal is provided not only at the top periphery of the base 60 butalso at the opening 66. It will be understood that spring washer 67 ineffect provides spring loading means for maintaining a predeterminedpressure on the sealing means 64 and 68. In order that the portion ofthe center stud nut 61 projecting below the base 60 does not interferewith supporting the coffee maker from a suitable surface, the base 60 ispreferably provided with a plurality of lug portions 60a at uniformlyspaced positions at the periphery thereof effectively defining legs.

So that the lower end of the handle 28 may be secured to the coifeemaker 20, the base 60 is provided with an extension 601; (FIG. 6)adjacent the top periphery thereof, which extension is provided with arecess 76 for receiving in interlocking relationship the lug 28c. Thus,the center stud nut 68 not only provides the two seals described abovebut also securely locks the lower portion of handle 28 to the vessel 21and base 60.

It is common practice with electrical appliances today to connect themto a source of electrical power through a power cord generallycomprising a female type connector adapted to make electrical connectionwith a male type bayonet or so-called pin contacts. To this end the base60 is provided with an outwardly opening recess 71 disposed immediatelybeneath handle 28 and having wall portions integrally molded with thebase 60. The inner wall of recess 71, designated by the referencenumeral 60c, is provided Wtih a pair of spaced openings 72 one of whichis shown in FIG. 6 of the drawings. These openings are adapted toreceive in sealed relationship therewith a pair of contact pins 73 and74. The terminal or contact pins 73 and 74 include a threaded portion73a and 76a, respectively, at an intermediate point therealong. Each ofthe contact pins 73 and 74 has the end thereof remote from the portionsprojecting into the recess 71 of tubular form extending through anO-ring supporting member identical for each terminal pin and designatedby the reference numeral 75. Moreover the tubular portion of terminalpins 73 and 74 extending through the O-ring supporting portion 75 arepeened over or riveted as indicated at 7311 and 74b, respectively, tosecure thereto not only the O-ring supporting members 75 but alsosuitable terminal connections as illustrated in FIG. 8 of the drawings.The contact pin 73 is riveted as indicated at 73b to electrically securethereto a terminal portion 76a of a rigid conductor element 76,- theother end of which is directly connected to terminal 56 of sheathedheating element 52. In a similar manner the corresponding end of contactpin 74 is riveted 'as indicated at 7412 electrically to secure thereto aterminal portion '77:: of rigid lead or conductor '77 which makeselectrical 8 connection with suitable switch means describedhereinafter.

In order to seal the openings such as 72 in wall portion 660, each ofthe O'ring supporting portions 75 is provided with an annular recess forreceiving 'an O-ring 79 (FIGS. 6 and 8). The contact pins 73 and 74 areinserted through the openings 72 and suitable nuts 80 are then appliedto the threaded portions 73a, respectively, whereby the rigid terminals73 and 74 are supported in spaced parallel relationship by the wallportion 60c, and the O-rings 7E9 insure that these openings 72 aresealed against the entrance of moisture. Preferably platelike washers 81are provided between the nuts 80 and wall 60c. These platelike washersmay be formed of stainless steel since they are exposed in the recess71.

In accordance with the present invention the main heating element 52 isutilized only during the coffee brewing operation to heat the bottom 30of the lower vessel 21 to a temperature in excess of 200 F. until allthe water in the lower vessel is forced into the upper vessel 22. Whenheating by the main heating element 52 is terminated, for the purpose ofkeeping the brewed coffee in the lower vessel 21 at a desirable servingtemperature of 160 to 180 F., there is provided a secondary heatingelement generally designated at 82 and best shown in FIGS. 5, 6, 8, and12 of the drawings. This auxiliary heating element comprises aninsulating core 83 (FIG. 12) of the shape of an annular segmentpreferably formed of mica or the like about which is wound a resistancewire schematically indicated in FIG. 8 of the drawings by the referencenumeral 84. If desired, the edges of the mica core 83 may be serrated toreceive the turns of the resistance wire 84. In a device built inaccordance with the present invention the resistance of the secondaryheating element 82 was such as to consume 40 watts of electrical energyand supply this as heat. In order to insulate the resistance wire 84secured on core 83, there are provided, as best shown in FIG. 12, topand bottom heater insulators 86 and 87 preferably, also, formed of micaor the like and of the same shape as core 33. A rigid backing plate 88also of the shape of elements 83, 86 and 87 is provided below the bottominsulator 87 and suitable hollow rivets 90 hold the elements 83, 84, 86,87 and 88 in assembled relationship as clearly indicated in FIG. 12 ofthe drawings.

The assembled secondary heater 82 is held against the bottom 30 of thevessel 21 in good heat exchange relationship, as clearly indicated inFIGS. 5 and 6 of the drawings, with the top insulator 86 in contact withthe vessel bottom 30. For the purpose of holding this heater inengagement with the vessel bottom 30, there is provided a combinedswitch mounting bracket and secondary heater clamping plate generallydesignated as 92. This plate 92 has an opening 91 for receiving the stud32 and is clamped into position by a nut 93 threadedly engaging the stud32. To perform this clamping function, combined switch mounting bracketand secondary heater clamping plate 92 is provided with an extension 92aincluding a pair of lateral projections 9212 each terminating in endprojections receivable in openings defined in raised protuberanccs 38aon backing plate 68, thus holding secondary heater 82 in intimate heatexchange relationship with the bottom 30 of vessel 21. Plate 9']. alsoincludes a forked projection 92c for receiving a weblike projection 60dfrom the wall 600 of base 6%) thereby preventing the base 60 fromrotating about the axis of stud 32.

The secondary heater 82 is provided with suitable terminals which areelectrically connected by insulated conductors 95 and 96 with thecontact pins 73 and 74, respectively. Thus, whenever electrical power isconnected to the contact pins 73 and 74, the secondary heater 82 isenergized.

As was mentioned above, it is desirable to terminate heating of thelower vessel 21 by the main heating element 52 when a substantialincrease in temperature of the bottom 30 occurs, due to all of the waterhaving been forced from the lower vessel 21 into the upper vessel 22. Tothis end there is provided a temperature responsive control meansgenerally designated by the reference numeral 98 which includes as animportant part thereof a bimetallic element 99 having one end fixed to aheat lug 100 (FIGS. 4, 5, 6 and 9). The heat lug 100 is indicated as anL-shaped member of good heat conducting material having one leg thereofbrazed to the bottom 30 of vessel 21. Preferably one end of-thebimetallic element 99 is clamped between the heat lug 100 and adepending projection 92d of plate 92, which projection is in spacedparallel relationship with one arm of the heat 'lug 100. Suitablefastening means 101 secures the end 'of bimetallic element to the heatlug 100 and projection 92d. The free end of bimetallic element 99 isprovided with an insulating switch actuating member 102 (FIG. 9) andupon heating of the vessel 21, the free end of bimetallic element 99tends to deflect upwardly as viewed in FIG. 9 of the drawings.

The temperature responsive device 98 further includes a snap actingswitch 103 comprising relatively movable contacts 103a and 103b, as bestshown in FIGS. 9 and 10 of the drawings. The snap acting switch 103includes operating means supported on a switch mounting arm 107 havingone end thereof secured to downwardly extending projections 92e ofcombined switch mounting plate and secondary heater clamp 92. The switchmechanism comprising the switch and operating means includes a stack ofconducting and insulating memberswhich are clamped to the free end ofswitch mounting arm 107 as illustrated in FIGS. 9 and 10 of thedrawings. This stack of elements comprises a contact spring stop 108formed of rigid material, a terminal portion 77b of terminal lead 77,movable contact supporting spring 109, a stationary contact supportingarm 110 having a terminal lug 110a, sheet insulators 111, 112 and 113,sleeve insulator 114, washer 115, and finally a rivet 116 which holdsall these elements in assembled relationship as clearly indicated inFIG. 10 of the drawings. The contact spring 109 comprises the well-knowntype of movable contact supporting element having a flexible rectangularouter frame member 109a and an integral central finger 10% supportingthe movable contact 10%. A suitable C-shaped toggle spring 117 has oneend connected to the finger 109!) and the other end connectedto theframe 109a. Deflection of the free end of the frame 109a in either oftwo directions will then cause the movable contact 10% to move with asnap action from the open position shown in FIG. 9 of the drawings wherethe finger 10% is against contact spring stop 108 to the closed positionwhere the contact 103b engages the stationary contact 103a or viceversa. The frame 109a has a portion thereof in the path of insulatingswitch actuating member 102 on the free end of bimetallic element 99 sothat upon deflection of bimetallic element 99 with heating, the switch103 is opened.

To complete the electrical circuit for the main heating element 52through the switch 103, there is provided, as best shown in FIGS. 5 and8 of the drawings, bus bar 119 of relatively rigid conducting materialconnected between terminal lug 110a of stationary contact supporting arm110 and the terminal 57 of the main heating element 52. Since theconductor 77 electrically connects the contact spring 109 and, hence,movable contact 10% with the contact pin 74, it will be obvious fromFIG. 8

' that when the switch 103 is closed, as indicated in FIG.

8 of the drawings, the main heating element 52 will be energized. Whenbimetallic element 99 is deflected by heating to the position of FIG. 9of the drawings, it will cause opening of the switch 103.

So that the switch 103 may be manually closed when desired, there issecured to the free end of contact spring 109 a bracket 120 supporting afork insulator 121. The

fork insulator 121 has a notch or recess 122 therein for receiving aswitch closing extension 123a of a member 123 operatively related toswitch control knob 124 described hereinafter and best shown in FIGS. 4and 7 of the drawings.

For the purpose of providing an initial adjustment for the temperatureat which the main heating element is rendered ineffective, there isprovided an adjustment screw 126 which is threaded into a speed nut 127mounted on another depending projection 92 of the plate 92. A suitablecontrol wheel 128 permits manual rotation of the adjustment screw 126.The free end of the adjusting screw 126 is adapted to engage the switchmounting arm 107 or the end of the rivet 116 so that the entire stack ofelements comprising the switch mechanism may be moved toward and awayfrom the bimetallic element 99. By rotating the adjusting screw 126 inone direction the switch mounting arm 107 is deflected toward thebimetallic element 99. Upon rotation of the adjusting screw 126 in theother direction it permits the inherent resilience of the switchmounting arm 107 to move the switch assembly away from the bimetallicelement 99. Preferably the base 60 is originally molded with a smallopening, not shown, disposed beneath the wheel 128 so that when thecoffee maker has been assembled, suitable tests can be run on the deviceand the wheel 128 adjusted by a suitable tool inserted through suchopening in the base 60. When the proper adjustment is obtained, thenthis opening may be sealed by a suitable plastic or similar sealingplug.

It is generally desirable to know when the brewing operation has beencompleted and to this end there is preferably provided a suitableindicating light designated at 130 supported by a lamp bracket 131,which bracket may be clamped by the fastening means 101 to the heat lug100. The lamp 130 is preferably a neon bulb and is connected across theterminals of the main heating element 52 by means of a conductor 133 anda conductor 134 and series current limiting resistor 135. Preferablythese conductors and the resistor are contained within suitableinsulating sleeves as best shown in FIG. 8 of the drawings. With thisarrangement the neon light 130 will be energized during the brewingoperation when the main heating element 52 is energized and when theswitch 103 is opened, the light 130 will be deenergized.

So that this light may be visible outside chamber 62, the base 60, asbest shown in FIGS. 4 and 7 of the drawings, is provided with an openingfor receiving a suitable lens 141. Preferably this lens is provided withan enlarged annular flange 141a receivable within a counter sunk portionsurrounding the outer edge of opening 140 and a sealing gasket or O-ring142 is provided to seal the opening 140 against the entrance ofmoisture. A suitable clamping element 143 engaging the inner wall ofbase 60 and engaging lens 141 holds the latter in position and,furthermore, clamps the O-ring 142 into sealing engagement between theflange 141a and the base 60.

It will be appreciated that the knob 124 must be outside the chamber 62,whereas the switch actuating member 123a is disposed within suchchamber. So that this can be accomplished while maintaining the chamber62 sealed against the entrance of moisture, the member 123 which is apivotal member is provided with a knurled portion 123b disposed withinan opening 145 in wall means defining the base 60. A suitable rubber orplastic resilient annular plug member or resilient diaphragm 146 ispreferably vulcanized or otherwise secured to the walls defining theopening 145 and to knurled portion 12%. The inherent resilience of themember 146 is such that limited movement of member 123 suflicient toactuate the switch 103 to the closed position can take place. The member123 includes a portion 1230 extending outside of chamber 62 and suitablysecured to portion 1230 is a knurled sleeve 148 cooperating with theknob 124. The base 60 surrounding the opening 145 is preferably providedwith an annular recess 149 for receiving an annular projection 124a anda plurality of spaced lugs 1241) extending from beyond such annularprojections. The lugs 12411 serve as stops engageable with cooperatingmembers in the annular groove 149 to limit the maximum pivotal movementof the knob 124. Preferably a suitable clamping member 150 engageablewith a groove in the member 148 holds the knob in assembled positionand, if desired, a decorative plate 151 may be secured to the front ofthe knob to hide the end of member 143, the member 150 and the member123. The portion 123a of member 123 is receivable within the notch 122of the fork insulator 121, so that upon rotation of the knob 124, thefork insulator and associated contact spring may be moved to theposition shown in FIG. 8 of the drawings. The portion 123a of the member123 does not interfere in any way with snap acting movement to theswitch open position of the contact spring 109.

From the above description it will be appreciated that there has beenprovided a simple automatic coiiee maker 20 which is inexpensive tomanufacture and which is foolproof in operation. Furthermore, by theimproved seal between the vessels, proper operation is assured and thehousewife can separate the vessels at the end of the brewing periodwithout any problem whatsoever. When the coffee making operation iscompleted, the main heating element is turned off and the secondaryheating element keeps the coffee in the lower vessel at a desirableserving temperature. The control switch is only actuated twice during acoffee making operation, once when the switch is closed by manualactuation of the knob 124 and finally at the termination of the brewingoperation when the bimetallic element moves the contact spring 109sufficiently to cause it to open the contacts with a snap action.Furthermore, the lower vessel 21 as well as the upper vessel 22 may becompletely immersed in liquid for cleaning purposes without any possibledamage to any of the electrical circuits.

While there has been shown and described a particular embodiment of thepresent invention, it will be understood that various changes andmodifications of the invention will occur to those skilled in the art.It is aimed in the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of the invention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. An automatically controlled electric coflee maker completelyimmersible in liquid for cleaning purposes comprising, a water heatingvessel, an electric heating element secured in intimate heat exchangerelationship with the bottom of said vessel, temperature responsivecontrol means including an electric circuit connected to control saidheating element, wall means defining a sealed housing secured to saidvessel and enclosing said heating element and temperature responsivecontrol means, means defining an opening in said wall means, a manualoperating means for said temperature responsive control means includinga pivotal member extending through said opening and movable from a firstposition to a second position and operatively associated with at least apart of said control means, and a resilient plug secured in said openingand bonded to said pivotal member for sealing said opening surroundingsaid pivotal member, said plug urging said pivotal member to said firstposition.

2. The cofi ee maker of claim 1 wherein said temperature responsivecontrol means includes a snap acting switch and a bimetallic element foractuating said switch to the open position upon predetermined heating ofsaid vessel, said pivotal member including means for operating saidswitch to the closed position.

3. The coffee maker of claim 1 wherein said wall means includes aninsulating cup-shaped base having a circular upper edge engageable withthe bottom of said vessel, 2.

stud depending from the center bottom of said vessel, means includingsaid stud for clamping said base to the bottom of said vessel, sealingmeans clamped between said circular upper edge and said vessel, andspring loading means for maintaining a predetermined pressure on saidsealing means.

4. The coffee maker of claim 1 additionally comprising a handle for saidvessel, said wall means including a cupshaped base having an upper edgeengageable with the bottom of said vessel, means including a studprojecting from the center bottom of said vessel for clamping said baseto the bottom of said vessel, and means for securing said handle to saidbase including interlocking portions, one on said handle and one on saidbase.

5. In an automatically controlled electric heating device thecombination of a vessel, 2. main electric heating element in intimateheat exchange relationship with the bottom of said vessel, a studdepending from the center bottom of said vessel, electric terminalsassociated with said vessel, temperature responsive control means incircuit with said main heating element and said terminals forcontrolling the energization of said main heating element and includinga switch, a secondary electric heating element in heat exchangerelationship with said vessel and directly connected to said terminalswhereby said secondary heating element is independent of saidtemperature responsive control means, an insulating cup-shaped basehaving a circular upper edge engageable with the bottom of said vesselto define a chamber for housing said control means, means including saidstud for clamping said base and said second heating element to thebottom of said vessel and for supporting said control means within saidchamber, means for manually operating said switch from its open to itsclosed position including a pivotal member extending through said base,a resilient sealing member sealing the area where said pivotal memberpasses through said base, means defining an aperture in the bottom ofsaid base for said stud, said stud extending through said aperture,sealing means clamped between said circular upper edge of said base andsaid vessel, spring loading means acting between said stud and said basefor maintaining a predetermined pressure on said sealing means, andmeans for sealing said aperture and said terminals.

6. The heating device of claim 5 additionally comprising a handlesecured to said vessel, and means for securing said handle to said baseincluding interlocking portions, one on said handle and one on saidbase.

'7. The heating device of claim 6 wherein said handle includes a portionconforming to the side of said vessel, and indicia means defined in saidvessel side visible both from the interior and exterior of said vessel,said portion of said handle overlying the indicia means visible from theexterior of said vessel.

References Cited by the Examiner UNITED STATES PATENTS 2,522,718 9/ 1950Huck. 2,522,420 5/1951 Frankel 219-441 2,692,937 10/1954 Clark 219-4362,817,743 12/1957 Foster 219-436 2,856,844 10/1958 Price 219-292 X2,860,229 11/1958 Ziegler 219-442 2,866,401 12/1958 Sidell 99-3122,896,062 7/1959 K-ueser 219-441 3,022,411 2/1962 Soper et a1. 219-4413,059,092 10/1962 Olson 219-441 3,135,189 6/1964 Jepson et al 219-441XFOREIGN PATENTS 907,269 6/ 1945 France. 193,595 12/1907 Germany.

ANTHONY BARTIS, Primary Examiner.

1. AN AUTOMATICALLY CONTROLLED ELECTRIC COFFEE MAKER COMPLETELYIMMERSIBLE IN LIQUID FOR CLEANING PURPOSES COMPRISING, A WATER HEATINGVESSEL, AN ELECTRIC HEATING ELEMENT SECURED IN INTIMATE HEAT EXCHANGERELATIONSHIP WITH THE BOTTOM OF SAID VESSEL, TEMPERATURE RESPONSIVECONTROL MEANS INCLUDING AN ELECTRIC CIRCUIT CONNECTED TO CONTROL SAIDHEATING ELEMENT, WALL MEANS DEFINING A SEALED HOUSING SECURED TO SAIDVESSEL AND ENCLOSING SAID HEATING ELEMENT AND TEMPERATURE RESPONSIVECONTROL MEANS, MEANS DEFINING AN OPENING IN SAID WALL MEANS, A MANUALOPERATING MEANS FOR SAID TEMPERATURE RESPONSIVE CONTROL MEANS INCLUDINGA PIVOTAL MEMBER EXTENDING THROUGH SAID OPENING AND MOVABLE FROM A FIRSTPOSITION TO A SECOND POSITION AND OPERATIVELY ASSOCIATED WITH AT LEAST APART OF SAID CONTROL MEANS, AND A RESILIENT PLUG SECURED IN SAID OPENINGAND BONEDED TO SAID PIVOTAL MEMBER FOR SEALING SAID OPENING SURROUNGINGSAID PIVOTAL MEMBER, SAID PLUG URGING SAID PIVOTAL MEMBER IN SAID FIRSTPOSITION.